Question-and-Answer Resource for the Building Energy Modeling Community
Get started with the Help page
Ask Your Question
1

Refrigeration Air Chiller System Evaporating Temperature, Constant or Variable - AirChiller

asked 2024-01-21 08:47:54 -0500

Zakaria's avatar

updated 2024-01-22 16:24:21 -0500

Hello everyone,

I am currently working on simulating a cold room storage using Refrigeration Equipment, and I am referencing the Refrigerated Warehouse example that utilizes the airchiller object - Fig.1 - (more details).

I have a question regarding the Refrigeration Air Chiller System Evaporating Temperature output variable, defined in the EnergyPlus documentation as the 'saturated evaporating temperature.'

I've plotted it over the simulation time and observed that it remains constant throughout, specifically at -24 °C, as specified in the 'Rated Cooling Source Temperature' within the airchiller object - Fig.2 -.

Can anyone clarify whether this value is expected to be constant during the simulation or if it should vary with time? Your insights would be greatly appreciated.

Thank you!

Fig.1 image description

Fig.2 image description

edit retag flag offensive close merge delete

1 Answer

Sort by » oldest newest most voted
0

answered 2024-01-22 05:25:11 -0500

Zakaria's avatar

updated 2024-01-22 05:29:26 -0500

I believe the output for the Refrigeration Air Chiller System Evaporating Temperature remains constant, corresponding to the Rated Cooling Source Temperature input for the air chiller. This conclusion is based on a simulation where the air chiller was OFF during the simulation runtime, and the Refrigeration Air Chiller System Evaporating Temperature consistently matched the -24°C which is exactly the Rated Cooling Source Temperature.

In the provided figure, the compressor's electric power and heat transfer rate, plotted on the left, both equil zero since the refrigeration system is turned off. Nevertheless, the evaporating temperature persists at -24°C ( on the right), precisely matching the Air Chiller's Rated Cooling Source Temperature.

Based on these observations, it seems that E+ does not independently calculate the evaporating temperature; rather, it appears to directly pass the Rated Cooling Source Temperature input as an output.

I would appreciate confirmation or additional insights from anyone familiar with this.

image description

edit flag offensive delete link more

Your Answer

Please start posting anonymously - your entry will be published after you log in or create a new account.

Add Answer

Training Workshops

Careers

Question Tools

1 follower

Stats

Asked: 2024-01-21 08:47:54 -0500

Seen: 55 times

Last updated: Jan 22